By JULIAN SHEA in London | China Daily Global | Updated: 2020-12-22 09:43 Share CLOSE Bones recovered from one of the world's most significant fossil sites have started a debate over whether some of the earliest human ancestors may have hibernated to survive harsh winters. In this undated image released by the Atapuerca Research Team (EIA) on March 26, 2008, a small piece of jawbone unearthed in a cave in Spain is seen. [Photo/Agencies] The site at Atapuerca, in Northern Spain, is known as the Sima de los Huesos, or Pit of Bones, and since the early 1980s, thousands of teeth and bones, some dating back more than 400,000 years, have been found, which are thought to belong to early Neanderthals or even their predecessors.